Anti-hypertensive efficacy of amlodipine dosing during morning versus evening: A meta-analysis

A meta-analysis was performed to compare the antihypertensive efficacy of morning and evening dosing. Database of Pubmed, Embase, Cochrane, Web of Science CNKI, VIP, and Wanfang were searched up to December 2018. A total of 19 randomized control trials and 1215 participants were included in this meta-analysis. Administration time of amlodipine did not affect the office blood pressure (RR = -0.03, 95% CI -0.93-0.88, P = 0.96), daytime blood pressure (RR = -0.30, 95% CI -1.05-0.46, P = 0.44), 24 h mean blood pressure (RR = 1.15, 95% CI -0.39-2.70, P = 0.14), or heart rate (RR = 0.11, 95% CI -1.22-1.45, P = 0.87). Administration of amlodipine in the evening could significantly reduce the nighttime blood pressure (RR = 2.04, 95% CI 1.27-2.81, P < 0.00001), increased non-dipper alteration (RR = 0.51, 95% CI 0.41-0.63, P < 0.00001), and contained better anti-hypertension efficacy (RR = 0.64, 95% CI 0.55-0.74, P < 0.00001). For patients with hypertension, especially for non-dipper hypertension, taking amlodipine in the evening will be more beneficial. Better quality trials conducted in different regions and with larger sample size are necessary to verify the conclusion of this study.